Machine vision technologies rely upon image processing and image analysis systems. Image processing systems manipulate raw video images through such processes as filtering, subtraction, and rotation, to generate other, enhanced images as output. Image analysis systems extract information from raw or processed video images to generate information or make decisions regarding the images.
This invention is in the field of image analysis.
The concern of the invention is determining characteristics of an object image, e.g., determining the angle of a rectilinear object image.
One prior art approach to determining the angle of an object is so-called "blob" analysis. This approach determines the angle of the principal axis of an image, among other things. This approach is ineffective for square objects because they have no principal axis. Furthermore, if there are perturbations in the outline of an object, such as a portion of a nozzle holding the object of interest showing beyond the periphery of the object, an erroneous result can likely occur.
Sometimes, the object of interest and the background can be distinguished easily, as by strong backlighting illumination, establishing a strong boundary. In other cases, methods known to those skilled in the art can be used to distinguish objects and background. It would be desirable to have a system to take advantage of such aspects of the image to produce a fast determination of the angle of the object. It is an object of the invention to produce a method and an apparatus for making such a determination.